Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;

.TH "SDL_SetClipRect" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetClipRect\- Sets the clipping rectangle for a surface\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBvoid \fBSDL_SetClipRect\fP\fR(\fBSDL_Surface *surface, SDL_Rect *rect\fR);
.SH "DESCRIPTION"
.PP
Sets the clipping rectangle for a surface\&. When this surface is the destination of a blit, only the area within the clip rectangle will be drawn into\&.
.PP
The rectangle pointed to by \fBrect\fR will be clipped to the edges of the surface so that the clip rectangle for a surface can never fall outside the edges of the surface\&.
.PP
If \fBrect\fR is \fBNULL\fP the clipping rectangle will be set to the full size of the surface\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_GetClipRect\fP\fR, \fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_Surface\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01